Ruby-throated Hummingbird, juv. male
It's so fun to watch hummingbirds this time of year at feeders. You have the maximum number of hummingbirds because there are both the adults and all the young birds. Many hummingbirds have begun migrating and this also swells the number of hummers you will see.
At our feeder is this Ruby-throated Hummingbird in juvenile plumage, the plumage they have when they leave the nest. They will start to molt this plumage in September and continue to molt into the following March, at which time all of their feathers will have been replaced. Usually the last feathers to be molted are the primaries (outer wing feathers) and gorget (throat feathers).
In general, both sexes of juvenile Ruby-throated Hummingbirds look a lot like the adult female at this time of year — they have whitish throats and white tips to their outer tail feathers.
At this time of year, it is easy to recognize juvenile hummingbirds because their plumage is all fresh and pristine, they often have paler edges to their crown feathers creating a scaled look, and sometimes their bills are slightly shorter than those of the adults. On the other hand, the adults’ feathers are worn (for the feathers are a year old) and the birds are beginning to molt, so they can look rather ratty.
You can tell that this juvenile is a male by seeing the little telltale blotch of red at the base of the throat (a sign of what is to come in the flashy red throat of the adult male). When he is an adult he will have a full red throat.
Check the hummers out at your feeder and see if you can spot the juveniles and adults.